1. Technical Field
The present invention generally relates to multi-node communication systems with shared resources. More particularly, the present invention relates to improving throughput in multi-node communication systems with shared resources and employing a shared resource access quota scheme.
2. Background Art
In the past, multi-node communication systems, such as local area networks, including both ring networks and bus networks, have managed node access to shared resources by limiting access thereto via mechanisms such as polling, random access, time slot and quota allocation mechanisms. The mechanisms proposed have generally attempted to provide fair access to the shared resources by the nodes. Some quota schemes have equalized the node throughputs by allocating the same quota to each node.
However, allocating the same quota to each node does not achieve optimum efficiency with regard to system throughput. The task of determining and tracking the allocation of different quotas among nodes is difficult and requires a large amount of information exchange, especially in systems where loading conditions fluctuate or loading is asymmetrical. Thus, most quota schemes have centered on the allocation of the same quota to all nodes. One such quota scheme is described in U.S. Pat. No. 4,926,418 issued to Cidon et al. and assigned to IBM (hereinafter, "the Cidon patent") the disclosure of, which is herein incorporated by reference in its entirety.
Thus, a need exists for improved efficiency in multi-node communication systems with shared resources employing a fixed quota scheme in order to allow for improved throughput in the case of an asymmetrically loaded system or a system whose load fluctuates.